DE102019111557A1 - Sensor and method for determining the geometric properties of a measurement object - Google Patents

Abstract

A sensor (10) for determining geometric properties of a measurement object, which is arranged in an object space (17), has an optical arrangement (14) and an evaluation and control device (16). The optical arrangement (14) has a first detector (12). The optical arrangement (14) defines a first focus profile (19) with a first maximum (39) along a first beam path line (18) in the object space (17). The optical arrangement (14) defines a second focus profile (21) with a second maximum (41) along a second beam path line (25) in the object space (17). The evaluation and control device (16) is set up to acquire a first measured value (22) of the first focus profile (19) and a second measured value (28) of the second focus profile (21). The evaluation and control device (16) is also set up to determine a focus control input variable (32) from the first measured value (22) and from the second measured value (28). The first focus profile (19) and the second focus profile (21) are coexisting focus profiles.

Description

The present invention relates to a sensor for determining geometric properties of a measurement object which is arranged in an object space, the sensor having an optical arrangement and an evaluation and control device, the optical arrangement having a first detector, the optical arrangement having a first Defined focus profile with a first maximum along a first beam path line in the object space, the optical arrangement defining a second focus profile with a second maximum along a second beam path line in the object space, the evaluation and control device being set up to measure a first measured value of the first focus profile and to acquire a second measured value of the second focus profile, the evaluation and control device further being set up to determine a focus control input variable from the first measured value and from the second measured value.

• - Bereitstellen eines Sensors mit einer optischen Anordnung und einer Auswerte- und Steuereinrichtung, wobei die optische Anordnung einen ersten Detektor aufweist, wobei die optische Anordnung ein erstes Fokusprofil mit einem ersten Maximum entlang einer ersten Strahlenganglinie in dem Objektraum definiert, wobei die optische Anordnung ein zweites Fokusprofil mit einem zweiten Maximum entlang einer zweiten Strahlenganglinie in dem Objektraum definiert,
• - Erfassung eines ersten Messwerts des ersten Fokusprofils und eines zweiten Messwerts des zweiten Fokusprofils mittels der Auswerte- und Steuereinrichtung, und
• - Bestimmung einer Fokusregelungseingangsgröße aus dem ersten Messwert und aus dem zweiten Messwert mittels der Auswerte- und Steuereinrichtung.

The invention also relates to a method for determining geometric properties of a measurement object, with the steps:

• - Providing a sensor with an optical arrangement and an evaluation and control device, the optical arrangement having a first detector, the optical arrangement defining a first focus profile with a first maximum along a first beam path line in the object space, the optical arrangement a second Defined focus profile with a second maximum along a second beam path line in the object space,
• - Acquisition of a first measured value of the first focus profile and a second measured value of the second focus profile by means of the evaluation and control device, and
• - Determination of a focus control input variable from the first measured value and from the second measured value by means of the evaluation and control device.

Such a sensor and method are off DE 10 2016 202 928 known.

In the case of imaging systems, the problem of focusing the system on, for example, a workpiece to be measured, i.e. the distance between the sensors and the workpiece to be measured must be set in such a way that an imaging depth that meets the requirements of measurement technology is achieved.

DE 38 28 381 C2 discloses a method and apparatus for automatically focusing an optical system. In the process, a search run is carried out and a focusing drive is stopped in a position corresponding to the maximum image contrast. A point of light or a mark is projected onto the object or cover glass surface and the position or shape of this point of light or this mark is used as the first focus criterion. The focusing drive is controlled to a position that corresponds to the first focus criterion. The search run is then carried out, the image contrast serving as the second focus criterion and the video signal of an image sensor being evaluated for this purpose.

DE 10 2016 202 928 A1 discloses a method for determining a focus-image distance of an optical sensor provided with an objective of a coordinate measuring machine in relation to the surface of a workpiece to be measured. The optical sensor can be moved relative to the workpiece in a Z direction, so that the distance in the Z direction between the workpiece and the optical sensor can be changed. The method has at least one of the following steps: a determination step in which the intensity of a first image recorded with the optical sensor of the surface of the workpiece to be measured at a first set focus distance and the intensity of a second image recorded with the optical sensor of the surface of the workpiece to be measured are evaluated at a second set focus distance in order to determine the most likely position of the best focus in relation to the first set focus distance and the second set focus distance; an approximation step in which at least three different focus distances are set in the vicinity of the most likely position of the best focus and the position of the best focus is approximately determined based on the intensity of the images recorded.

The disadvantage of the two methods mentioned is that it is time-consuming to record image series with changing distances from the object.

There is a desire to provide a sensor that can efficiently perform a wide range of optical measurement tasks at comparatively low costs. Accordingly, it is an object of the present invention to specify a corresponding sensor and a corresponding method.

According to one aspect of the present invention, this object is achieved by a sensor and a method of the type mentioned at the beginning, wherein the first focus profile and the second focus profile are coexisting focus profiles.

The geometric property can be, for example, a distance between two features on the measurement object, the length of an edge, the diameter of a hole or a complex free form on the surface of the measurement object.

The object space can in particular be a space outside the sensor. The sensor can for example have a housing. The object space can for example be a space outside the housing of the sensor. The measurement object is preferably located in the object space. As an alternative to this, a reference object can also be located in the object space when the method is carried out.

The optical arrangement can be arranged within the housing and one or more optical elements selected from a group of optical elements comprising a lens, a mirror, a glass plate, a diaphragm, a polarizer, a filter, for example a polarization filter, a prism and a polarizer exhibit. The specific arrangement of the optical elements can have at least one beam path, for example a first beam path and / or a second beam path. The first beam path and / or the second beam path can have the first beam path line and / or the second beam path line. For example, a first beam path of the optical arrangement can have the first beam path line and a second beam path of the optical arrangement can have the second beam path line. As an alternative to this, the first beam path can have both the first beam path line and the second beam path line.

The first beam path and / or the second beam path can include both a set of beam path lines, in particular the first beam path line and / or the second beam path line, and the optical elements which define the beam path lines.

The first beam path line and the second beam path line can represent possible courses of light beams in the optical arrangement, the possible courses of light beams in the optical arrangement being defined by means of the optical arrangement. By means of light rays, the propagation of light is modeled in the context of geometric optics. The light rays can form a bundle of light rays which can be represented as a set of beam path lines.

The corresponding beam path lines, in particular the first beam path line and / or the second beam path line, can be calculated from the configuration of the optical arrangement. The beam path lines, in particular the first beam path line and / or the second beam path line, can be determined, for example, from the configuration of the optical arrangement by means of matrix optics.

The beam path lines, in particular the first beam path line and / or the second beam path line, can in particular be determined by the design of the optical arrangement and by the properties of the light emanating from the measurement object or a reference object. Alternatively, the first beam path and / or the second beam path can be determined experimentally.

The first detector can for example have a camera, in particular a red-green-blue (RGB) camera. The first detector can in particular be set up to detect an incident light beam. The first beam path line can, for example, connect the same optical elements as the second beam path line. In this way, optical elements and thus costs can be saved. Furthermore, the sensor can hereby be made compact.

Alternatively, the first optical path line can at least partially connect different optical elements than the second optical path line. For example, the first beam path line can touch at least one optical element which does not touch the second beam path line. For example, the second beam path line can also touch at least one optical element which does not touch the first beam path line. In this way, a difference can be generated between the first focus profile and the second focus profile in order to determine the focus control input variable without shifting an optical component of the optical arrangement and / or the sensor to the measurement object, in particular to save costs and increase time efficiency.

The optical arrangement can be designed in such a way that the first beam path line can be partially identical to the second beam path line. This saves optical components and reduces costs. As an alternative to this, the optical arrangement can be configured in such a way that the first beam path line is configured separately from the second beam path line.

The first focus profile and / or the second focus profile can preferably be a one-dimensional path in the object space. The first focus profile and / or the second focus profile can be part of a multiplicity of focus profiles, for example a group Focus profiles. The set of focus profiles can in particular be defined by the optical arrangement.

The first focus profile and / or the second focus profile can, for example, reflect a focus criterion as a function of a distance. For example, the first focus profile and / or the second focus profile can reflect a focus criterion as a function of a distance to a reference point, for example to a part of the sensor.

For example, the first focus profile can reflect a first focus criterion as a function of a distance. The second focus profile can reflect a second focus criterion as a function of a distance. The first focus criterion can be identical to the second focus criterion. Alternatively, the first focus criterion can differ from the second focus criterion. Advantageously, the first focus criterion and / or the second focus criterion can be used to infer a distance from a focus point. The first focus criterion and / or the second focus criterion can, for example, provide information about the proportion of photons from a virtual point light source at a respective point of the first focus profile or the second focus profile would meet again at a point on the first detector.

The first focus criterion and / or the second focus criterion can be selected from a group of focus criteria comprising a contrast, a light intensity, a light intensity as a function of a light frequency, and an image sharpness. The focus criteria mentioned can advantageously be determined without additional optical components in the sensor, for example by means of an optical image and an evaluation of the optical image by means of the evaluation and control device.

The first focus profile can be, for example, a first focus criterion as a function of a perpendicular projection onto an optical axis. The second focus profile can be, for example, a second focus criterion as a function of a perpendicular projection onto an optical axis. In this way, for example, two one-dimensional focus profiles for determining the focus control input variable can be defined within the three-dimensional object space.

The first focus profile and / or the second focus profile can in particular be defined by optical elements of the optical arrangement. The first focus profile can preferably be configured differently from the second focus profile. For example, the first focus profile can be spatially displaced in relation to the second focus profile. In this way, the focus control input variable can be determined without a spatial displacement of an optical element and / or the sensor relative to the measurement object.

The first beam path line and / or the second beam path line can be arranged at least partially within the housing and at least partially in the object space. The optical elements of the optical arrangement can preferably be arranged within the housing. For example, the evaluation and control device can be set up to acquire the first measured value of the first focus profile and the second measured value of the second focus profile by determining a focus criterion, for example the first focus criterion and / or the second focus criterion.

For example, the evaluation and control device can be set up to acquire a first contrast value as the first measured value of the first focus profile. Furthermore, the evaluation and control device can be set up to record a second contrast value as a second measured value of the second focus profile. A contrast value can be suitable as a focus criterion because it is easy to determine. The contrast value can be determined, for example, by comparing the brightness of two neighboring points in an image, with the image being able to be determined by means of the sensor. For this purpose, no additional optical components of the optical arrangement are advantageously necessary.

For example, the evaluation and control device can be set up to determine the focus control input variable from the first measured value and from the second measured value by means of a mathematical operation. The mathematical operation can preferably be such that it can be used to infer both an amount of the focus control input variable and a sign of the distance excitation input variable.

For example, the evaluation and control device can be set up to determine a distance between an object point in the object space and a reference point, for example part of the sensor, from the first measured value and from the second measured value. In this way, for example, a necessary change in the optical arrangement and / or a change in the distance between the sensor and the measurement object can be determined in order, for example, to obtain a sharp image of the measurement object.

For example, the evaluation and control device can be set up to determine the focus control input variable from the first measured value and from the second measured value and from a stored calibration. An autofocus method can hereby be carried out inexpensively.

The first focus profile and the second focus profile can be coexisting focus profiles from a family of coexisting focus profiles. Both the first focus profile and the second focus profile can be identical to the first focus profile and the second focus profile at the time of the acquisition of the second measured value at the time of the acquisition of the first measured value. For example, the optical detection of the first measured value and the second measured value can be kept constant. For example, the optical arrangement can be kept constant during a time period within which both the first measured value and the second measured value are recorded. The first focus profile and the second focus profile can preferably exist during the acquisition of the first measured value. Furthermore, the first focus profile and the second focus profile can exist during the acquisition of the second measured value. This makes it possible, for example, to dispense with a motor for a temporal variation of the optical arrangement and thus for a temporal variation of a focus profile. In this way, both manufacturing costs and operating costs can be saved. Since motors are usually susceptible to wear, this can increase the reliability of the sensor.

The first beam path line can preferably be unequal to the second beam path line. For example, the first beam path line can start from a different object point in the object space than the second beam path line. As a result, the focus control input variable can be determined, for example, without changing the optical arrangement over time and a motor can be dispensed with, which can lead to cost savings and a robustness of the sensor.

For example, a light source can be used to acquire the first measured value and / or to acquire the second measured value, for example a chromatic light source. Preferably, no light source is necessary to acquire the first measured value and / or to acquire the second measured value. In particular, the acquisition of the first measured value and / or the acquisition of the second measured value can be carried out without using a light source, in particular without using a light source integrated into the sensor. By dispensing with a light source, in particular a light source integrated into the sensor, costs can be saved and / or the robustness of the sensor can be increased.

The sensor can in particular be set up to determine the focus control input variable efficiently and cost-effectively.

The focus control input variable can in particular provide information on focusing an imaging system. The focus control input variable can serve to adjust the optical arrangement or an optical arrangement of a separate imaging system in such a way that light beams emanating from a measuring point of a measuring object meet at a point of the first detector or the detector of the separate system. The focus control input variable can be used, in particular, to carry out an autofocus method. For example, the evaluation and control device can be set up to focus an image by means of the focus control input variable, preferably by means of only a change in a distance. For example, the focus control input variable can be detected without changing the optical arrangement. In particular, the focus control input can be determined without using a motor.

The above The task is therefore completely solved.

The evaluation and control device can be designed to determine the focus control input variable by forming the difference between the first measured value and the second measured value. The evaluation and control device can particularly preferably be set up to subtract the first measured value from the second measured value or to subtract the second measured value from the first measured value. By determining the focus control input variable by means of a difference formation, in particular a point of an asymmetrical function can be determined from the first measured value and from the second measured value. The point of the asymmetrical function can preferably be used to infer both an amount of the focus control input variable and a sign of the focus control input variable. For example, the focus control input variable can specify both a distance from a focal plane and the direction of the distance.

As an alternative or in addition to this, the evaluation and control device can be designed to determine the focus control input variable or a further focus control input variable from the first measured value and a third measured value or from the second measured value and a third measured value. For example, the optical arrangement can define a third focus profile with a third maximum along a third beam path line in the object space. The third beam path line can be part of a third beam path of the optical arrangement. The evaluation and Control device can be set up to acquire a third measured value of the third focus profile. In this way, for example, the focus control input variable can be adjusted or made more precise, for example by averaging the focus control input variable and the further focus control input variable.

In the context of the present invention, the terms “first”, “second” and “third” are to be understood as designations, without any reference to a sequence or an indication of whether there are any further elements mentioned.

The optical arrangement can for example have an imaging beam path. The imaging beam path can, for example, form main optics of the optical arrangement. The imaging beam path can in particular be set up to generate images, in particular high-resolution images. The imaging beam path can be set up, for example, to generate images, in particular high-resolution images, by means of the first detector. As an alternative to this, the imaging beam path can be set up to generate images, in particular high-resolution images, by means of an image detector. For example, the imaging detector can be designed independently of the first detector. The sensor can, for example, be an additional device for a camera with the image detector.

The imaging beam path can preferably be designed to be telecentric. In particular, this can minimize the influence of any defocusing on a measurement result in which a lateral expansion of the measurement object is to be determined and / or evaluated by means of the image.

The optical arrangement can have a device for changing the focus. In particular, the imaging beam path can have the device for changing the focus. The imaging beam path can in particular have a device for changing the focus. The device for changing the focus can for example have a motor, in particular a motor for translating an optical element, for example a motor for translating a lens.

The evaluation and control device can be designed to sharpen the imaging beam path with respect to the measurement object by means of the focus control input variable, for example by means of the device for changing the focus. For example, the evaluation and control device can be designed to apply the focus control input variable to the device for changing the focus, in particular as a signal for performing a translation, for example a translation of a lens.

The optical axis may be an axis which an imaging light beam follows when imaging is in focus.

The optical arrangement can be designed such that a distance to the measurement object, for example from a part of the sensor to the measurement object, can be determined by examining the first beam path line and / or the second beam path line.

The sensor can in particular be set up to determine the focus control input variable without a relative displacement of an element relative to an object point in the object space, for example to a measurement object. For example, the evaluation and control device can be set up to determine the focus control input variable only by means of the first measured value and the second measured value. In order to determine the focus control input variable, no further measured value is necessary in addition to the first measured value and the second measured value. As a result, a measurement object can be focused within a short time, in particular by just one translation step.

The evaluation and control device can have at least one stored calibration in order to infer the focus control input variable by means of the first measured value and the second measured value, in particular by means of a difference between the first measured value and the second measured value. The focus control input variable can preferably have a value for a translation and also a direction for a translation. The sensor can be set up, for example, to carry out the translation by means of the device for changing the focus. The device for changing the focus can in particular be designed to change a focus profile of the imaging beam path, in particular such that the measurement object can be imaged sharply.

The sensor can, in particular, be designed in order to only require a motor for changing the imaging beam path, but not a motor for determining the focus control input variable. The sensor can preferably only have a device for displacing an element of the imaging beam path, but not a device for displacing an element which is touched by the first beam path line and / or by the second beam path line. For example, the sensor can be designed without a motor and only a separately designed one The imaging system with the imaging beam path can have a motor for focusing.

The focus control input variable can represent, for example, a distance from an origin of a coordinate system, the origin of the coordinate system representing a focal point of the imaging beam path. The focus control input variable can preferably contain not only an amount but also a direction for achieving a control goal. The control target can be an arrangement of the optical arrangement in which the measurement object can be imaged sharply by means of the imaging beam path, for example by means of the first detector or by means of the imaging detector. The focus control input variable can represent, for example, a function value of an asymmetrical function, in particular an asymmetrical function as a function of a distance. The function value of the asymmetrical function can in particular be generated by forming the difference between the first measured value and the second measured value.

The control target can in particular be a zero crossing of the asymmetrical function. The asymmetrical function can preferably have the zero crossing at a point of a maximum focus criterion of the imaging beam path. The asymmetrical function can preferably have a maximum gradient in the vicinity of the control target, for example in order to determine deviations from the control target with the greatest possible sensitivity. For example, the evaluation and control device can be set up to use the first measured value and the second measured value to infer both a direction and an amount for achieving the control target, in particular for the required focus shift in the imaging beam path, without performing a translation.

The sensor can preferably be designed to focus the imaging beam path with respect to the measurement object in one step using only a single focus control input variable, determined only from the first measurement value and the second measurement value. The device for changing the focus can preferably be set up in order to focus the imaging beam path with regard to the measurement object in a single step.

For example, the optical arrangement can be designed in such a way that a capture range and a steepness of the asymmetrical function are optimized or can be optimized for the respective measurement conditions. A large capture area is associated with large initial distances from the focus, which can be eliminated by means of the method. The steepness corresponds to an accuracy with which the focus can be set, in particular by means of only a single translation step.

The first focus profile and / or the second focus profile can, for example, be optimized or can be optimized by means of a configuration of the optical arrangement with regard to the capture area and an accuracy of the focusing of the imaging beam path. An optimization of the optical arrangement with regard to a more suitable asymmetrical function can be achieved, for example, by varying the distance between two optical elements and / or by changing a depth of field and / or changing a numerical aperture, for example by means of adjustable diaphragms and / or by a Change of the focus criterion, for example the first focus criterion and / or the second focus criterion. The optimization can take place, for example, during manufacture or in operation, for example in an application-related manner.

Optimization of the optical arrangement with regard to a capture range and / or an accuracy of focusing the imaging beam path with regard to the measurement object can for example have a hardware approach and / or a software approach. For example, the evaluation and control device can be set up to optimize the capture range and / or the accuracy on the software side, for example by varying the mathematical operation for determining the focus control input variable. For example, the optical arrangement can be optimized in such a way that the first focus profile and / or the second focus profile can be varied to optimize a capture range and / or a measurement accuracy to achieve the control target, in particular on the software and / or hardware side.

An enlargement of the capture area can, for example, be accompanied by a reduction in accuracy, for example when a distance between a focal plane of the first focus profile and a focal plane of the second focus profile is increased.

The first beam path line can be at least partially part of the imaging beam path. In particular, the first beam path line and / or the second beam path line can be at least partially identical to a beam path line of the imaging beam path. Alternatively or additionally, the second beam path line can be at least partially identical to a beam path line of the imaging beam path. For example, the first beam path line and / or the second beam path line can be completely identical to a beam path line of the imaging beam path. For example, the first beam path line can be partially be identical to the second beam path line. The measures mentioned can, for example, reduce production costs and / or installation space and / or weight.

The optical arrangement can be set up such that the first maximum has a first half-width and that the second maximum has a second half-width. When displaying the first focus profile and the second focus profile as a function of a perpendicular projection onto an axis, a distance between the first maximum and the second maximum can be 0.1 to 4 times, preferably 0.5 to 2.5 times. times, particularly preferably 1.0 to 1.7 times, the mean value of the first half width and the second half width. In this way, both a useful capture range and a useful accuracy can preferably be achieved.

The axis can be, for example, an optical axis, preferably the optical axis of the imaging beam path. The distance between the first maximum and the second maximum can be achieved, for example, by changing the optical arrangement and / or by changing the evaluation and control device on the software side. The first half width and / or the second half width and / or the distance between the first maximum and the second maximum can be varied, for example, by varying a focal length of one or more lenses of the optical arrangement. To reduce the first half-width, a focal length of a lens of the optical arrangement can be reduced along the first beam path line, for example the last lens in front of the measurement object along the first beam path line. To reduce the second half-width, a focal length of a lens of the optical arrangement can be reduced along the second beam path, for example the last lens in front of the measurement object along the second beam path.

The origin of the asymmetrical function can preferably image the best focus position of the imaging beam path. A distance between the first maximum and the second maximum can in particular correspond to the capture range. A large distance between the first maximum and the second maximum can correlate with a large capture range for achieving the control objective. A large distance between the first maximum and the second maximum can correlate with a low steepness of the asymmetrical function about the origin, and thus with a low accuracy of the achievement of the control goal. The regulation of the regulation target can in particular be carried out by means of a single step.

The mentioned exemplary and preferred distances between the first maximum and the second maximum can in particular optimize a ratio of the capture range to an accuracy.

In the method, the sensor can preferably be arranged in such a way that the measurement object or a reference object is located in a plane perpendicular to the axis between the first maximum and the second maximum. This can in particular ensure that the measurement object and / or the reference object are located in the capture area.

The first detector can be set up to detect the first measured value by means of a first light beam emanating from an object. The optical arrangement can be set up to guide the first light beam along the first beam path line from the object to the first detector. The first detector can further be set up to detect the second measured value by means of a second light beam emanating from the object. The optical arrangement can be designed to guide the second light beam along the second beam path line from the object to the first detector. The optical arrangement can be set up such that an object plane of the first light beam is preferably unequal to an object plane of the second light beam. The object can be the measurement object or the reference object, for example. The object can be the measurement object, for example. Alternatively, the object can be a reference object.

The first light beam and / or the second light beam can be, for example, light from the environment that is scattered on the measurement object or on the reference object, in particular in the direction of the first detector. In this way, for example, a light source in the sensor can be saved and thus costs and / or weight and / or installation space can be saved and / or the durability of the sensor can be increased.

As an alternative to this, the first light beam and / or the second light beam can be a light beam which is directed by the sensor onto the object by means of a light source and is reflected from there back to the sensor. In this way it can be achieved, for example, that the sensor can also be used in the absence of ambient light.

The object plane of the first light beam can in particular be a plane from which a measurement object or a reference object is sharply imaged onto the first detector, in particular by means of the first light beam. The object plane of the second light beam can in particular be a plane from which the measurement object or a reference object is sharply imaged onto the first detector, in particular by means of the second light beam.

For example, the optical arrangement can be set up to guide the second light beam along the second beam path line from the object to a second detector. The second detector can be identical to the imaging detector, for example. The second detector can be integrated in the sensor, for example. Alternatively, the second detector can be arranged separately from the sensor. In this way, for example, a separation of the first light beam from the second light beam can be simplified, for example by completely separate beam paths or by spatial separation of the first beam path from the second beam path prior to detection.

The first detector and / or the second detector can for example have a matrix sensor, in particular a CCD sensor or a CMOS sensor. Alternatively or in addition, the first detector and / or the second detector can have a photodiode.

For example, the object plane of the first light beam can be unequal to the object plane of the second light beam. Alternatively or additionally, the object plane of the first light beam and / or the object plane of the second light beam can be different from an object plane of the imaging beam path. In this way, a capture range can in particular be achieved if a further focus control input variable is to be determined by means of the imaging beam path or if the imaging beam path is to be used to acquire the first measured value or the second measured value. An inequality of the object planes of the first light beam and / or the second light beam and / or the imaging beam path can in particular lead to the expression of the asymmetrical function, resulting from the configuration of the optical arrangement. In this way, for example, a capture area can be achieved.

The object plane of the first light beam can, for example, have an angle to the object plane of the second light beam and / or the imaging beam path. The angle can preferably be an angle not equal to 0 °. For example, the angle can be an angle between 10 ° and 80 °, preferably between 30 ° and 60 °, particularly preferably from 40 ° to 50 °.

By means of the angle between the object plane of the first light beam and the object plane of the second light beam and / or the object plane of the imaging beam path, in particular as a result of the configuration of the optical arrangement, a first focus profile can be generated which is different from the second focus profile and / or a first focus profile which is configured differently to a focus profile of the imaging beam path.

For example, the object plane of the first light beam can be tilted to the object plane of the second light beam and / or to the object plane of the imaging beam path. For example, the first object plane and / or the second object plane can not be arranged perpendicular to the optical axis of the imaging beam path. For example, the first object plane and / or the second object plane can not be arranged perpendicular to the object plane of the imaging beam path. In this way, for example, the imaging beam path can also be used to determine the focus control input variable, for example in order to increase the measurement accuracy.

For example, the object plane of the first light beam, in particular by means of a tilted mirror, can be offset and / or tilted to the object plane of the second light beam and / or to the object plane of the imaging beam path. An offset and / or tilting of the object plane of the first light beam relative to the object plane of the second light beam and / or relative to the object plane of the imaging beam path can take place, for example, by means of at least one optical element. The optical element can be selected from a group of optical elements having a tilted mirror, a tilted lens, a decentered lens, a lens without correction of a chromatic longitudinal aberration, a chromatic longitudinal undercorrected optics.

The angle can be generated, for example, by means of reflection via a mirror and superposition of the first light beam by means of a beam splitter cube with the second light beam and / or with the imaging beam path. For example, the mirror can be designed to introduce the angle. For example, one or more tilted and / or decentered lenses can be used instead of the mirror. However, a design with a tilted mirror can be advantageous, since by means of the tilted mirror a beam comprising the first light beam is preferably perpendicular to the object plane of the first light beam. The optical element can preferably be chromatically-longitudinally undercorrected. The optical element can, for example, be longitudinally undercorrected chromatically by diffractive and / or polarization-optical effects.

For example, the object plane of the first light beam can be offset from the object plane of the second light beam. Alternatively or additionally, the object plane of the first light beam and / or the object plane of the second light beam can be offset with respect to the object plane of the imaging beam path. The object plane of the first light beam can be arranged, for example, parallel to the object plane of the second light beam and / or parallel to the object plane of the imaging beam path. For example, the object plane of the second light beam can be arranged parallel to the object plane of the imaging beam path. For example, the object plane of the first light beam and / or the object plane of the imaging beam path can be offset from the object plane of the second light beam in such a way that a capture area and / or an accuracy can be optimized for a measurement situation.

For example, the first measured value and the second measured value can be recorded simultaneously, for example by means of a single image using the first detector. In this way, for example, an autofocus method can be accelerated. Furthermore, this can reduce measurement errors in the event of a relative movement between the measurement object and the sensor.

For example, the evaluation and control device can be set up to acquire the first measured value and the second measured value at two positions of an image field of an image, in particular by acquiring a focus criterion at two positions of the image field, for example at an upper edge and at a lower edge of the Field of view. In particular, the asymmetrical function can be generated in this way.

By means of the angle between the object plane of the first light beam and / or the object plane of the second light beam and / or the object plane of the imaging beam path, image content can be sharply imaged at the edges of an image sensor, for example the first detector, at different distances, for example the sensor from the measurement object . In this way, a distance, in particular a distance between the measurement object and a part of the sensor, can be selected as a reference point at which object points lying on the optical axis have the sharpest image.

By means of the angle, functional curves that are lagging or running ahead can result for a focus criterion at an upper edge of the image compared with a lower edge of the image or compared with an image of another beam path. By forming the difference between a focus criterion at the upper edge of the image and a focus criterion at the lower edge of the image, for example, the focus control input variable can be detected.

For example, the object plane of the first light beam and / or the object plane of the second light beam and / or the object plane of the imaging beam path can have a common point on the optical axis, for example around the first focus profile and / or around the second focus profile for direct focusing of the imaging beam path use.

For example, the first light beam and the second light beam can form a light beam. The light beam can emanate, for example, from the measurement object or from the reference object. For example, the first light beam and the second light beam can form a light beam between the measurement object or the reference object and the first detector. As an alternative to this, the first light beam and the second light beam can only form a light beam between the measurement object or the reference object and a beam splitter.

For example, the first light beam can be part of a light beam. Alternatively or additionally, the second light beam can be part of a light beam. For example, the first beam path line can be at least partially part of the first beam path. The second beam path line can be at least partially part of the second beam path. For example, the first beam path line can be part of the first beam path as well as part of the second beam path. For example, the first beam path can be a common beam path for the first light beam and for the second light beam, the first light beam and the second light beam forming a light beam.

By forming a light beam from the second light beam and the first light beam, the sensor can, for example, be optimized with regard to a number of optical elements and costs and / or installation space can be saved.

The optical arrangement can for example have a separating device. The separating device can be configured to separate the first light beam from the second light beam. Alternatively or additionally, the separating device can be set up to separate the first light beam and / or the second light beam from an imaging light beam. For example, the Separating device be designed to separate light beams by color. For example, the separating device can be set up to separate the first light beam from the second light beam and / or from the imaging light beam sequentially in terms of color, for example by means of color-configured lighting. The separating device can for example be a red-green-blue (RGB) camera, for example in connection with an RGB-X cube, in particular an RGB-X cube.

For example, the sensor can have a chip pattern, for example an RGB Bayer pattern. Alternatively, a different pattern can also be used. For example, the first detector can be a hyperspectral sensor.

The separating device can be set up, for example, to achieve a temporal separation. A temporal separation can be achieved for example by means of sequential recordings, for example by means of sequential switching of diaphragms. A temporal separation can be particularly advantageous if the number of pixels in the first detector is to be low, for example in order to reduce costs.

For example, the first light beam can only be separated from the second light beam and / or from the imaging light beam on the first detector. The first detector can have a camera chip, for example. In this way, for example, greater freedom can be achieved in the optical design, in particular in the design of the optical arrangement, and / or lower light losses. For example, a beam splitter may not be necessary here. This saves costs and installation space.

For example, the separating device can have two separate detectors, for example the first detector and the second detector. Separation can be achieved here by means of the separate detectors. Alternatively, a separation can take place such that one half of the first detector, for example an RGB camera chip, is used to acquire the first measured value and another half of the first detector is used to acquire the second measured value and / or for high-resolution imaging. As an alternative to this, a separation can be achieved by means of different colors, for example over the entire surface of the first detector.

For example, the use of equal angles between the object plane of the first light beam and / or the object plane of the second light beam and / or the object plane of the imaging beam path can be advantageous, for example with regard to stabilizing the first measured value and / or the second measured value against influences of a surface of the object.

The optical arrangement can have at least one beam splitter. The beam splitter can be an optical element selected from the group comprising a beam splitter cube, a Glenn-Thompson polarizer, an RGB-X cube, a beam splitter with a green bandpass, for example a notch filter, and a glass plate. For example, the notch filter can be set up in order to achieve a division of non-green components into two partial beams which have an identical spectral composition.

The optical arrangement can be designed to use the beam splitter to superimpose the first light beam with the second light beam and / or split the first light beam from the second light beam. For example, the optical arrangement can be set up to superimpose the imaging light beam and / or a third light beam on the first light beam and / or the second light beam by means of the beam splitter. For example, the first light beam and / or the second light beam and / or the third light beam and / or the imaging light beam can reach the first detector via common optics.

The sensor can be designed, for example, to generate the third measured value by means of a third light beam emanating from the measurement object. The third light beam can be, for example, the imaging light beam. The third light beam can be guided to the first detector by means of the third beam path, for example.

The first beam path and / or the second beam path and / or the third beam path and / or the imaging beam path can at least partially form a common beam path. For example, the second beam path can be quasi-identical to the third beam path. In this way, for example, a transformation into a frequency domain can be used and / or costs can be saved. For example, a selection with which the focusing is to be quantified can thereby be possible.

Preferably, positions of all elements traversed by the first light beam relative to the measurement object and the position of all elements traversed by the second light beam relative to the measurement object and positions of all elements traversed by the third light beam relative to the measurement object during the detection of the first and / or the second measured value must be identical to those during the acquisition of the third measured value.

For example, the optical arrangement can have three beam paths, in particular the first beam path and the second beam path and the third beam path, which can each be arranged at an angle of 120 ° parallel and around the axis, in particular parallel and around the optical axis of the imaging beam path. In particular, the optical arrangement can be designed in such a way that as few or no optical elements as possible are arranged in the vicinity of the axis, for example in order to be able to achieve compression by folding the beam paths.

For example, an object plane of the third beam path can be unequal to the object plane of the second beam path and / or the object plane of the third beam path. In particular, an object plane of the third light beam can be unequal to the object plane of the second light beam and / or the object plane of the third light beam. The object plane of the third beam path can for example have an angle, in particular an angle not equal to 0 °, to the object plane of the first beam path and / or to the object plane of the second beam path and / or to an object plane of the imaging beam path. For example, the object plane of the third beam path can be arranged offset to the object plane of the second beam path and / or to the object plane of the third beam path and / or to the object plane of the imaging beam path. For example, the object plane of the third beam path can be tilted to the object plane of the imaging beam path and / or to the object plane of the first beam path and / or to the object plane of the second beam path. For example, the object plane of the first beam path and / or the object plane of the second beam path and / or the object plane of the third beam path can not be arranged perpendicular to the optical axis of the imaging beam path, but tilted, for example by means of a tilted mirror and / or a tilted lens and / or a decentered lens.

For example, the second detector can be set up to use it to detect the first light beam and / or the second light beam and / or the third light beam and / or the imaging light beam. The second detector can particularly preferably be set up to detect the image of the imaging beam path, in particular a sharp image.

For example, the sensor can be set up to acquire several first measured values and / or several second measured values and / or several focus control input variables in parallel, for example simultaneously. For example, the evaluation and control device can be set up to select which first measured value and / or which second measured value and / or which focus control input variable is used, for example which focus control input variable is used to act on the device for changing the focus, in particular to achieve the target value as precisely as possible . For example, mean values of the first measured values and / or the second measured values can be used to determine the focus control input variable.

For example, the sensor can be set up to project suitable features for detecting a focus criterion onto the measurement object or onto the reference object. For example, by reflecting a marker arrangement in the optical arrangement, for example in the first beam path and / or in the second beam path and / or in the third beam path, suitable features for determining the focus criterion can be focused on the measurement object or on the reference object.

The reference object and / or the measurement object can be designed, for example, planar. As an alternative to this, the reference object and / or the measurement object can be configured in a non-planar manner. A surface of the measurement object and / or a surface of the reference object can be arranged, for example, perpendicular to the optical axis. As an alternative to this, a surface of the measurement object and / or a surface of the reference object can be arranged at an angle other than 90 ° to the optical axis.

The sensor can be used in particular for focus control for imaging systems. The sensor can in particular be set up to generate a focus control input variable suitable for focus determination and / or focus control by means of individual images of imaging systems, for example by means of the first beam path and / or the second beam path. In this way, for example, measurement processes can be significantly accelerated. For example, there is no need to record a so-called autofocus image stack. In particular, dynamic operation with a moving measurement object or moving sensor can be possible.

The kit for retrofitting has an interface to the sensor. The interface can preferably be an electronic interface. For example, the kit can have a kit housing. The kit can be advantageous in that it can be connected to the sensor by means of the interface if required and the sensor only has to have one beam path, namely the imaging beam path. This can save costs when purchasing the sensor and the kit can be used at Can be used with different sensors for autofocusing. This can also save costs. When worn, either the kit or the sensor can be replaced, which also saves costs and reduces waste.

The invention also relates to a coordinate measuring machine having a sensor as described above. The coordinate measuring machine can for example have at least one further sensor, for example at least one tactile sensor. The coordinate measuring machine can have at least one probe arm. For example, the sensor can be integrated in the probe arm. For example, the probe arm can be designed to move the sensor relative to the measurement object.

The coordinate measuring machine can have a base on which a workpiece holder can be arranged. The workpiece holder can be a cross table, for example. The workpiece holder can be set up, for example, to fix the measurement object and / or to move the measurement object relative to the base.

The coordinate measuring machine can for example have a column on which the probe arm can be displaceably mounted. The probe arm can have a measuring head. The further sensor and / or the sensor can for example be arranged at least partially in the measuring head.

The coordinate measuring machine can have a controller. For example, the evaluation and control device of the sensor can be at least partially integrated in the controller. As an alternative to this, the evaluation and control device of the sensor can for example be integrated in the measuring head.

The invention further relates to a kit for retrofitting a sensor for determining geometric properties of a measurement object which is arranged in an object space. The sensor has an optical arrangement and an evaluation and control device. The optical arrangement has a first detector. The optical arrangement has an imaging beam path. The optical arrangement defines a first focus profile with a first maximum along the imaging beam path in the object space. The evaluation and control device is set up to acquire a first measured value of the first focus profile. The kit has an interface to the sensor. The kit has an optical supplementary arrangement. The supplementary optical arrangement defines a second focus profile with a second maximum along a second beam path line in the object space. The interface to the sensor is set up to apply a second measured value of the second focus profile to the evaluation and control device of the sensor.

The kit for retrofitting a sensor can, for example, have an electrical interface and / or an electronic interface and / or a mechanical interface to the sensor. The interfaces, in particular the mechanical interface and / or the electronic interface and / or the electrical interface, can in particular be set up to interact with the sensor. The interface to the sensor can in particular be set up to apply a second measured value of the second focus profile to the evaluation and control device of the sensor, in particular to focus a measurement object with respect to the imaging beam path and with respect to the first detector or an imaging detector.

The evaluation and control device can in particular be set up to determine the focus control input variable from the first measured value, which is recorded by means of the sensor, and from the second measured value, which is recorded by means of the retrofitting kit, the first focus profile, which is recorded by means of of the sensor is defined, and the second focus profile, which is defined by means of the kit for retrofitting, are coexisting focus profiles.

The advantage of the kit for retrofitting a sensor can be seen in the fact that the kit can be added to a sensor at a later date, for example in order to enable an autofocus method to be carried out. In this way, a sensor can be adapted to changed requirements, in particular in a cost-effective and environmentally friendly manner.

In the method for determining geometric properties of a measurement object, the first focus profile and the second focus profile are coexisting focus profiles, as described above.

In particular, a method for determining geometric properties of a measurement object can be carried out by means of the coordinate measuring device or the sensor, which method can be carried out in a very short time. To focus the sensor with respect to the measurement object, it is not necessary to ensure an optimal position of the sensor in relation to the measurement object over a longer period of time. The method can be suitable in particular for focus regulation in dynamic operation. In particular, the sensor has little outlay in terms of equipment. An influence of surface properties of the measurement object can be in the new sensor and the new process.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the present invention.

In particular, the features mentioned above and those yet to be explained below can only be combined with the preamble of the independent claims.

• 1A eine schematische Darstellung eines ersten Ausführungsbeispiels des neuen Sensors;
• 1 B Fokusprofile und eine Fokusregelungseingangsgröße in Abhängigkeit eines Abstands zu dem ersten Ausführungsbeispiel des neuen Sensors;
• 1C Fokusregelungseingangsgrößen in Abhängigkeit eines Abstands für unterschiedliche erste Strahlenganglinien und zweite Strahlenganglinien zu dem ersten Ausführungsbeispiel;
• 1D Fokusprofile und Fokusregelungseingangsgrößen in Abhängigkeit eines Abstands für verschieden stark auszeichnende Fokusprofile des ersten Ausführungsbeispiels;
• 2 ein zweites Ausführungsbeispiel des neuen Sensors;
• 3 ein drittes Ausführungsbeispiel des neuen Sensors;
• 4 ein viertes Ausführungsbeispiel des neuen Sensors;
• 5A ein fünftes Ausführungsbeispiel des neuen Sensors;
• 5B eine Darstellung eines Teils des ersten Detektors des fünften Ausführungsbeispiels des neuen Sensors;
• 6 ein sechstes Ausführungsbeispiel des neuen Sensors;
• 7 ein siebtes Ausführungsbeispiel des neuen Sensors; und
• 8 ein Ausführungsbeispiel des neuen Koordinatenmessgerätes.

Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

• 1A a schematic representation of a first embodiment of the new sensor;
• 1 B Focus profiles and a focus control input variable as a function of a distance to the first exemplary embodiment of the new sensor;
• 1C Focus control input variables as a function of a distance for different first beam path lines and second beam path lines from the first exemplary embodiment;
• 1D Focus profiles and focus control input variables as a function of a distance for focus profiles of the first exemplary embodiment which have different strengths;
• 2 a second embodiment of the new sensor;
• 3 a third embodiment of the new sensor;
• 4th a fourth embodiment of the new sensor;
• 5A a fifth embodiment of the new sensor;
• 5B a representation of part of the first detector of the fifth embodiment of the new sensor;
• 6th a sixth embodiment of the new sensor;
• 7th a seventh embodiment of the new sensor; and
• 8th an embodiment of the new coordinate measuring machine.

1A shows a first embodiment of the new sensor 10 . The new sensor 10 is used to determine the geometric properties of a measurement object that is in an object space 17th is arranged.

The sensor 10 has an optical arrangement 14th and an evaluation and control device 16 on. The optical arrangement 14th has a first detector 12th on. The optical arrangement 14th defines a first focus profile 19th with a first maximum 39 along a first optical path line 18th in the object space 17th . It also defines the optical arrangement 14th a second focus profile 21st with a second maximum 41 along a second optical path line 25th in the object space 17th . The evaluation and control device 16 is set up to take a first reading 22nd of the first focus profile 19th and a second measured value 28 of the second focus profile 21st capture. The evaluation and control device 16 is also set up to use the first measured value 22nd and from the second measured value 28 a focus control input 32 to determine. The first focus profile 19th and the second focus profile 21st are coexisting focus profiles that define the optical arrangement 14th for example defined at the same time at each point in time.

The evaluation and control device 16 is preferably designed to use a difference formation from the first measured value 22nd and from the second measured value 28 the focus control input 32 to determine, such as in 1 B shown.

1B shows the first focus profile 19th and the second focus profile 21st depending on a distance 38 . The first focus profile and the second focus profile can, for example, each be used as a focus criterion as a function of a distance 38 , especially as a contrast depending on a distance 38 , be shown. 1B particularly shows the focus control input 32 depending on a distance 38 obtained from forming the difference from the first measured values 22nd and from second measured values 28 . The focus control input 32 depending on the distance 38 typically forms an asymmetrical function due to the difference formation. 1D shows three first focus profiles 19th and three second focus profiles 21st , as well as the focus control input variable 32 depending on a distance 38 for the three associated first focus profiles 19th and second focus profiles 21st .

The optical arrangement 14th of the first embodiment forms an imaging beam path 34 and can be a focus changing device 36 exhibit. In the first embodiment, the device for changing focus 36 at least one along an optical axis 60 Have sliding lens. The evaluation and control device 16 is preferably designed to use the focus control input variable 32 the imaging beam path 34 to focus with respect to the measurement object.

The device for changing focus 36 can be set up around the imaging beam path 34 to focus with respect to the measurement object. The first optical path line 18th of the first embodiment is at least partially part of the imaging beam path 34 .

In the 1B and 1D are exemplary first focus profiles 19th and second focus profiles 21st depending on a perpendicular projection onto an axis 60 shown. The optical arrangement 14th can in particular be set up in such a way that the first maximum 39 a first half width 40 and that the second maximum 41 a second half width 42 having.

With different distances between the first maximum 39 and the second maximum 41 different functions of the focus control input variable 32 depending on a distance 38 result, for example in 1C shown. 1C shows three different functions of the focus control input 32 depending on a distance 38 , in particular depending on a perpendicular projection onto the axis 60 . The functions of the focus control input 32 could for example from first measured values 22nd and second measured values 28 to be determined. When compared to the first half width 40 and / or to the second half width 42 large distance between the first maximum 39 and the second maximum 41 can be a function of the focus control input 32 depending on a distance 38 have only a slight steepness for an optimal focus point in the vicinity of the optimal focus point, which can make regulation to the optimal focus point more difficult and / or can worsen the accuracy of the regulation to the optimal focus point, but a capture range can be large. When compared to the first half width 40 and / or to the second half width 42 small distance between the first maximum 39 and the second maximum 41 can be a function of the focus control input 32 depending on a distance 38 Although they have a higher steepness for an optimal focus point in the vicinity of the optimal focus point, the capture range can then be very small. An area can be viewed as a capture area in which the focus control input variable is clearly derived 32 the distance and the direction to the optimal focal point can be inferred. A range between the first maximum 39 and the second maximum 41 to be viewed as.

A distance 24 between the first maximum 39 and the second maximum 41 can for example be 0.1 to 4 times, preferably 0.5 to 2.5 times, particularly preferably 1.0 to 1.7 times the mean value of the first half width 40 and the second half width 42 be.

The first detector 12th can be set up to take the first reading 22nd by means of a first light beam emanating from an object 20th capture. The optical arrangement 14th can be set up to the first beam of light 20th along the first optical path line 18th from the object to the first detector 12th to lead, for example in 1A shown. The first detector 12th can be set up to take the second reading 28 by means of a second light beam emanating from the object 26th capture. The optical arrangement 14th can be set up to the second light beam 26th along the second optical path line 25th from the object to the first detector 12th to lead, as also in 1A shown.

An object plane of the first ray of light 44 can be unequal to an object plane of the second light beam 46 his. The object plane of the first ray of light 44 can be an angle 49 to the object plane of the second light beam 46 , as in 1A shown have. The first ray of light 20th and the second beam of light 26th can, as in 1A shown, a light beam 50 form that emanates from the measurement object.

For example, the optical arrangement 14th a separator 58 exhibit. The separator 58 can be set up to the first beam of light 20th from the second ray of light 26th to separate.

The optical arrangement 14th can use a beam splitter 52 have, for example in 1A shown. The optical arrangement 14th can be set up by means of the beam splitter 52 a superposition of the first light beam 20th with the second ray of light 26th or a division of the first light beam 20th from the second ray of light 26th to achieve. For example, as in 1A shown, the optical arrangement 14th be set up by means of the beam splitter 52 a superposition of the first light beam 20th and the second light beam 26th with the imaging beam path 34 to achieve.

The sensors shown in the figures 10 have an imaging beam path 34 on. By means of the imaging beam path 34 can be an image, in particular the actual measurement image, on the first detector 12th , preferably a camera. The imaging beam path 34 can preferably be designed telecentrically, for example to prevent any defocusing to minimize the result of measurements, in particular in the case of measurements in which a lateral expansion of measurement objects in the image is to be determined or evaluated. The optical arrangement 14th can have a first beam path 96 and a second beam path 98 exhibit. The first beam path 96 can be the first optical path line 18th have and be adapted to the first light beam 20th respectively. The second beam path 98 can be the second optical path line 25th have and be arranged to the second light beam 26th respectively. Using the first beam path 96 and / or by means of the second beam path 98 In particular, a distance between the sensor and the measurement object can be detected.

The 1A , 2 , 3 , 5A , 6th and 7th show in particular sections of optically imaging systems which image one or more object planes on the right onto one or more image planes on the left. 4th shows a section of an optical imaging system in which one or more object planes on the left are imaged onto one or more image planes on the right. In the 1A , 2 , 3 , 4th , 5A , 6th and 7th In the illustrated embodiments, a device for the spatially resolving registration of incident photons, preferably the first detector, is located in the image plane 12th . In particular, there is the first detector 12th when setting the best focus distance within the image plane of the imaging beam path 34 . For example, it can be the first detector 12th be a matrix sensor.

The representation after 1A For graphical simplification and / or illustration, has properties which are not advantageous in the case of an apparatus-based implementation and can therefore be changed. To explain the principle, the selected representation can, for example, be a representation with offset image planes of the imaging beam path 34 to the image planes of the first beam path 96 and / or the second beam path 98 his.

The first beam path 96 and / or the second beam path 98 can in particular have object planes which are not perpendicular to the optical axis 60 of the system, i.e. to the optical axis 60 of the imaging beam path 34 , are arranged. In particular, the object plane of the first light beam 44 and / or the object plane of the second light beam 46 with respect to the object plane of the imaging beam path 34 be inclined, for example by the angle 48 , as in 1A shown. The angle 48 can, as in 1A shown, are generated by the fact that the beam splitter 52 with the imaging beam path 34 superimposed first ray of light 20th and the second beam of light 26th over a mirror 53 be reflected. The mirror 53 can in particular be set up at a corresponding angle 48 to introduce.

Alternative to the mirror 53 tilted and / or decentered lenses can be used for the same purpose. However, the selected configuration with a tilted mirror can be advantageous 53 because in this case the bundle of rays comprising the first light beam 20th and the second beam of light 26th , is perpendicular to the object plane. A distance from the object plane of the imaging beam path 34 to the object plane of the first light beam 44 and / or to the object plane of the second light beam 46 can as in 1A be formed shown, but can also by a corresponding choice of the design and positioning of the first beam path 96 and / or the second beam path 98 be designed differently. For example, the object plane of the imaging beam path 34 at the same height as the optical axis 60 be arranged like the object plane of the first light beam 44 and / or the object plane of the second light beam 46 .

1 B shows three courses of a focus criterion, in particular three focus profiles, as a function of a distance, in each case in arbitrary units 38 of the measurement object from the image plane of the imaging beam path 34 , i.e. from the optimal focus position. The focus criteria can in particular be variables that are determined by means of the first detector 12th can be detected, for example by means of an image on a camera. The measurement object or a reference object can be arranged, for example, in such a way that the surface from which the first light beam 20th and / or the second light beam 26th proceed perpendicular to the optical axis 60 of the imaging beam path 34 is arranged. As an alternative to this, this surface can also be at an angle other than 90 ° to the optical axis 60 be arranged.

Due to an angle of the object plane of the first light beam 44 and / or the object plane of the second light beam 46 and / or the object plane of the imaging beam path 34 Image content at the edges of the image field and on an axis can be added to the surface 60 of the image field at different distances from the sensor 10 are sharply mapped to the measurement object.

In case of 1 B is the distance at which the sharpest image is on the optical axis 60 lying object points is chosen as a reference point so that the abscissa is a distance 38 of the optimal focus position. Through an inclined object plane of the first light beam 44 and / or the second light beam 46 to the surface can be lagging and / or leading functional courses for the focus criterion plotted on the ordinate result. For example, a first beam path line 18th starting from an upper edge of an image, a trailing or leading course of a first focus profile 19th have in comparison to a second focus profile 21st , which leads to a second optical path line 25th starting from a lower edge of an image heard.

By forming the difference between the first measured value 22nd , for example a focus criterion on the upper edge of the image, and the second measured value 28 , i.e. a focus criterion at the lower edge of the image, can also be used in 1 B Focus control input variable shown 32 to be determined. The functional dependence of the focus control input variable 32 from the distance 38 from the best focal plane can be used for autofocusing.

The function of the focus control input variable shown 32 depending on a distance 38 indicates for the implementation of an autofocus method in comparison to the profile of the focus criterion for the imaging beam path which is also shown 34 , especially as a third measured value 56 presented numerous advantages.

The function of the focus control input 32 depending on a distance 38 is especially asymmetrical with respect to the reference point, i.e. with respect to the control target. Using the mathematical operations from the first measured value 22nd and the second measured value 28 obtained function of the focus control input quantity 32 depending on a distance 38 Not only an amount but also a direction for setting the control target can be determined. A slope of the function of the focus control input variable can preferably be used at the control target 32 depending on a distance 38 be maximum, in particular such that deviations from the control target can be determined with the greatest possible sensitivity.

For example, the first function can be the focus control input variable as a function of the distance 72 the 1C from closely spaced first beam path 18th and second optical path line 25th result, for example from the first beam path line close to the axis 18th and near-axis second beam path line 25th . The second function of the focus control input as a function of the distance 74 also results from the first measured values 22nd and second measured values 28 , however, the starting points of the first ray of light 20th and the second light beam 26th are further apart, especially in the plane of the angle. 1C also shows a third function of the focus control input variable as a function of the distance 76 . The third function 76 also results from the first measured values 22nd and second measured values 28 , however, the starting points of the first ray of light 20th and the second light beam 26th are further apart, in particular in the plane of the angle., compared to the functions 74 and 72 .

1C particularly shows differences in functions of the focus control input variable 32 depending on a distance 38 which can result from the fact that, in one case, image areas close to the axis are used to determine the first measured values 22nd and the second measured values 28 can be used and in the other case image areas at opposite edges of a field of view are used. It can be clearly seen that the functions shown work differently for regulating and / or measuring a distance 38 suitable for the control objective. The focus control inputs 32 the edges of the image can have a larger capture area, such as in function 76 especially when compared to the other two functions 72 and 74 . However, the third is function 76 around the control target not very sharp excellent, so using the third function 76 no particularly stable and / or precise focus regulation could be realized. If a more stable focus control with a smaller capture range is required, the second function could 74 be more suitable, as this is steeper at the zero crossing. The first function 72 , i.e. with the focus control input variables generated close to the axis 32 , is disadvantageous in every respect, since it has neither a large capture range nor a sharp marking. In terms of control technology, the third function 76 be well suited for slow tracking in the event of large deviations from the control target and the second function 74 could be optimal for faster regulation in the event of smaller deviations from the control target.

As in the third function 76 the 1C shown, it can happen with sharp focus criteria, that is, with sharp focus profiles, and / or with a large distance between the object planes that the focus control input variable 32 no longer clearly defines the control target. In such cases, for example, the optical arrangement 14th can be modified in such a way that there are no inflection points of the function of the focus control input variable at the zero crossing 32 depending on a distance 38 more surrender. Alternatively or additionally, a numerical aperture, for example the first beam path 96 and / or the second beam path 98 can be changed by adjustable panels. This could allow a depth of field to be adjusted in each case so that it is always in a selected area of the field of view a signal optimized for focus control can be generated.

Instead of adjusting the depth of field by changing the optical arrangement 14th can for example also on the software side by means of the evaluation and control device 16 a focus criterion with a different focus depending on the field position can be selected. This could also change the shape of the function of the focus control input variable 32 depending on a distance 38 can be optimized for focus control. In principle, the focus control input variable is used to optimize the function 32 depending on a distance 38 both hardware approaches and software approaches are conceivable.

1D shows three functions of the first measured value 22nd depending on a distance 38 as well as three functions of the second measured value 28 depending on a distance 38 and further three functions of the focus control input 32 depending on a distance 38 .

The fourth function 78 shows first measured values 22nd from a lower edge, being the fourth function 78 has a mediocre award. The fifth function 80 shows second measured values 28 from an upper edge of a figure, being the fifth function 80 has a mediocre award. The sixth function 82 shows the focus control inputs 32 , which results from the first measured values 22nd the fourth function 78 and the second measured values 28 the fifth function 80 surrender.

A seventh function 84 shows first measured values 22nd from a lower edge of a figure, being the seventh function 84 a sharp distinction, especially when compared to the fourth function 78 , having. An eighth function 86 shows second measured values 28 from an upper edge of a figure, being the eighth function 86 a sharp distinction, especially when compared to the fifth function 80 , having. The ninth function 88 shows the focus control inputs 32 , which is based on the first measured values 22nd the seventh function 84 and the second measured values 28 the eighth function 86 surrender. The ninth function 88 has a sharp distinction, for example compared to the sixth function 82 on.

A tenth function 90 shows first measured values 22nd of a lower edge of a figure, being the tenth function 90 has a poor distinction, especially in comparison to the seventh function 84 and to the fourth function 78 . An eleventh function 92 shows second measured values 28 from an upper edge of a figure, being the eleventh function 92 has a poor distinction, especially when compared to the eighth position 86 and / or to the fifth function 80 . A twelfth function 94 shows focus control input variables 32 resulting from the tenth function 90 and from the eleventh function 92 surrender. The twelfth function 94 has a poor distinction, especially when compared to the ninth position 88 and the sixth function 82 . The twelfth function 94 can be most beneficial for autofocusing compared to the ninth function 88 and to the sixth function 82 as the twelfth function 94 compared to the ninth function 88 and the sixth function 82 has the greatest slope around the control target.

2 shows a second embodiment of the new sensor 10 . This in 2 The illustrated embodiment can in principle like that in 1A illustrated embodiment be designed. This in 2 The illustrated second embodiment shows an embodiment of the first beam path 96 and the second beam path 98 how it can arise if parallel object planes are sought instead of object planes tilted against each other. The angle of incidence on the object plane of the first light beam 44 or on the object plane of the second light beam 46 are in such a case no longer symmetrical to an optical axis 60 of the first beam path 96 or the second beam path 98 . This can result in, for example, disruptive perspective effects, in particular when viewing non-planar measurement objects. This can be a disadvantage, for example, when imaging by means of the first beam path 96 and / or an image using the second beam path 98 should also be used for lateral measurements, since the required post-processing effort can be higher than with the one in 1A illustrated first embodiment. The in 2 illustrated embodiment can for example by rotating the sensor 10 around the angle 48 normal imaging conditions can be created again.

This in 3 The third embodiment shown can in principle also like the first embodiment as in 1A be shown designed. The third exemplary embodiment has several first beam paths 18th and several second optical paths 25th on. The in 3 The illustrated embodiment was, in particular for illustration, again a different distance between the object planes of the imaging beam path 34 and the object planes of the first ray paths 44 and the second beam paths 46 elected.

A separation of the imaging beam path 34 from the first ray paths 18th and the second beam paths 25th is designed here, for example, as a spectral separation. The beam splitter 52 can be designed as an RGB-X-Cube, for example and can preferably be combined with an RGB camera as the first detector 12th . As an alternative to the spectral separation of the beam paths, a temporal separation would also be conceivable, for example by means of a sequential recording of images of the object plane of the first light beam 44 , the object plane of the second light beam 46 and the object plane of the imaging beam path 34 , for example by means of switching diaphragms. This can be useful, for example, if a number of pixels in the first detector 12th should be kept low, so that an RGB version of the sensor 10 too low pixel densities for a sufficiently dense scanning of the object space 17th would exhibit.

For example, the imaging beam path 34 of the in 3 The illustrated embodiment be set up to an image by means of green light on the first detector 12th to focus. With the imaging beam path 34 For example, it can be a high-resolution beam path suitable for the lateral measurement of measurement objects. For example, the first beam paths 18th and the second ray paths 25th be set up to red and / or blue light to determine the distances between the object planes of the first light beam 44 and the object planes of the second light beam 46 from part of the sensor 10 or from a reference point. For example, focus criteria, for example first measured values, can be spatially resolved both by means of a red light beam and by means of a blue light beam 22nd and / or second measured values 28 , be determined.

By forming the difference from the first measured values 22nd and second measured values 28 a location-dependent focus control input variable can be detected. For example, it can be advantageous if the object plane of the imaging beam path 34 and the object plane of the first light beam 44 and the object plane of the second light beam 46 a common point on the optical axis 60 , especially on the optical axis 60 of the imaging beam path 34 , have, for example, in such a way that the imaging beam path 34 and / or the first beam path 96 and / or the second beam path 98 for direct focusing of the imaging beam path 34 can be used.

In principle, a similar approach can be used instead of object planes tilted towards one another, for example one opposite the object plane of the first light beam 44 tilted object plane of the second light beam 46 , can also be tracked with parallel object planes. An approach with parallel object planes can have the advantage that also on the optical axis 60 of the imaging beam path 34 a signal that is well suited for focus control could be generated, in particular without rotating the sensor 10 . However, when using parallel object planes, the object planes would have to be offset parallel to one another in order to achieve a meaningful focus control input variable 32 to obtain.

To be a function of the focus control input 32 depending on a distance 38 To optimize or change it, several possibilities are conceivable, in particular to optimize a relationship between the capture range and the steepness in the control target for a respective application. For example, in order to change the function of the focus control input variable 32 depending on a distance 38 to achieve a change in the optical arrangement 14th and / or a change in the focus criterion used. A size of the capture area for focus regulation depends, for example, on a distance between the object plane of the first light beam 44 to the object plane of the second light beam 46 from, for example, a distance from parallel object planes. Furthermore, the size of the capture area can depend on an angle by which the object planes are inclined to one another.

4th shows a fourth embodiment of the new sensor 10 , wherein in the fourth embodiment, parallel object planes are acceptable and / or desired. In the in 4th The illustrated embodiment is the object plane of the first light beam 44 parallel to the object plane of the second light beam 46 arranged. In particular, the optical arrangement 14th of this exemplary embodiment designed in such a way that the optical arrangement 14th an object plane of the first light beam 44 defines which is parallel to an object plane of the second light beam 46 , where also the object plane of the second light beam 46 from the optical arrangement 14th is defined. The optical arrangement also defines here 14th an object plane of the imaging beam path 34 which are parallel to the object planes of the first light beam 44 and the second light beam 46 is arranged.

In principle, the fourth exemplary embodiment can be designed like the first exemplary embodiment. The object plane of the first ray of light 44 is opposite the object plane of the second light beam 46 offset. Also in 4th are the object planes of the first beam path for illustration purposes only 44 and the object plane of the second light beam 46 clearly compared to the object plane of the imaging beam path 34 offset. For example, the object plane of the imaging beam path 34 also identical to the object plane of the first light beam 44 or the object plane of the second light beam 46 his.

The optical arrangement 14th can in particular be designed such that the object plane of the first light beam 44 and the object plane of the second light beam 46 serve a distance measurement. A distance from the object plane of the first light beam 44 with respect to the object plane of the second light beam 46 can in particular by appropriate design of the optical arrangement 14th can be adapted in such a way that a desired combination of capture area and best focus location can be achieved. The in 4th The illustrated embodiment is an image of the object plane of the first light beam 44 , the object plane of the second light beam 46 and the object plane of the imaging beam path 34 via a common main optics on three separate beam paths, identified by the reference symbols 96 , 98 and 34 .

The fourth embodiment may be a separator 58 have, the separating device 58 is set up to the first beam of light 20th from the second ray of light 26th , and preferably from an imaging light beam. The separator 58 can preferably be an RGB-X-Cube. Alternatively or additionally, however, the first light beam can be separated 20th , the second ray of light 26th and the imaging light beam via separate cameras, for example by means of the first detector 12th and a second detector, take place and / or sequentially in time via switched apertures or sequentially in terms of color via color-switched lighting.

In the fourth exemplary embodiment, it can be particularly advantageous that there are two quasi-identical imaging strands. For example, the first beam path 96 and / or the second beam path 98 as imaging beam paths 34 serve, in particular as additional imaging beam paths. This can, for example, enable a transformation into a frequency domain for the focus criterion. For example, it can be selected with which beam path, in particular with which beam path line, a focusing is to be quantified and with which beam path an image, in particular a high-resolution image, is to be made. Furthermore, for example, two beam paths can be selected to provide a focus control input variable 32 to create. For example, two or even three measured values can be recorded simultaneously for each location in the field of view to determine the best focus position.

For example, by means of the evaluation and control device 16 several focus criteria can be calculated in parallel. For example, by means of the evaluation and control device 16 the focus criterion for the most suitable focus control input variable can be selected 32 leads.

Alternatively or additionally, there could be chromatic effects, for example a chromatic longitudinal aberration in the optical arrangement 14th , are included, for example about an object plane of the first light beam 44 with respect to an object plane of the second light beam 46 to move. Chromatic longitudinal aberration can cause the focus profile, in particular the focal length, to be color-dependent in imaging systems. In this way, for example, a distance between two object planes can be realized in a very stable manner, since this is a property of the glasses used in the optical arrangement 14th acts, which is usually very stable against external influences.

That in the 5A and 5B illustrated fifth embodiment of the new sensor 10 can also basically like the embodiment of 1A and 1B be designed. In particular, the fifth embodiment can be like that in 4th illustrated fourth embodiment. However, this can be done in 5A The illustrated embodiment uses a beam splitter instead of the RGB-X-Cube 52 have, which can be coated with a green bandpass, for example a notch filter. For example, the beam splitter 52 be designed in such a way that it divides non-green components into two light beams, which then have an identical spectral composition. In particular, the beam splitter 52 be designed in such a way that it merges the beam into the first light beam 20th and the second beam of light 26th can divide or unite.

For example, the optical arrangement 14th of the fifth embodiment of the new sensor 10 have chromatic-longitudinal-undercorrected optics. For example, the sensor 10 Inclined object planes of the first light beam offset from one another by a chromatic longitudinal error 44 and the second light beam 46 exhibit. In particular, the object plane of a first beam path can 96 with respect to an object plane of a second beam path 98 be offset and / or inclined. The focus control input variable can, for example, by means of a first beam path line 18th of the first beam path 96 and a second optical path line 25th of the first beam path 96 or by means of a first beam path line 18th and a second optical path line 25th of the second beam path 98 can be determined, in particular using object planes that are offset in parallel to one another. As an alternative to this, the focus control input variable can be made using a first beam path line 18th of the first beam path 96 and a second optical path line 25th of the second beam path 98 are detected, in particular using object planes inclined to one another. An image of two object planes inclined to one another can for example on each part, for example one half, of the first detector 12th , in particular an RGB camera chip. For example, an image of the object plane of the imaging beam path can be used 34 on the first detector 12th be done entirely in terms of green light. In particular, green light can be used for the imaging beam path 34 enable utilization of the entire detector surface.

5B shows a chip pattern of the first detector 12th of the in 5A shown embodiment of the new sensor 10 . The chip pattern is shown as an example of an RGB Bayer pattern. For example, other patterns can also be used, in particular so-called hyperspectral sensors, with which, for example, several inclined object planes that are chromatically shifted relative to one another can be recorded. This in 5A and 5B The illustrated embodiment shows an example of an embodiment in which the same angle of incidence is present at every location of the object planes inclined relative to one another, regardless of color. In this way, for example, the measurement results can be stabilized with respect to influences of the surface of the measurement object or the reference object. For example, the in 5A illustrated embodiment, a second detector can be used. It would also be possible to use further detectors.

In the 6th and 7th are exemplary embodiments of the sensor 10 shown in which the optical arrangement 14th is designed such that a superposition of the first light beam 20th with the second ray of light 26th and with the imaging beam path 34 only on the first detector 12th , especially on the camera chip of the first detector 12th , he follows. This can, for example, provide greater freedom in the design of the optical arrangement 14th enable and can, for example, reduce light losses, for example because no beam splitter is passed through.

The ones in the 6th and 7th The illustrated embodiments can in principle be arranged like the first embodiment. The ones in the 6th and 7th The illustrated embodiments can be advantageous when realizing three beam paths with object planes inclined to one another. The three beam paths can, for example, each be offset by 120 ° around the optical axis 60 of the imaging beam path 34 be arranged. This can be the case with the in 7th The illustrated embodiment can be easily implemented, since no optical elements close to the axis are required here. This in 7th The illustrated embodiment can be advantageous, for example, with regard to a compression by folding the beam paths, for example because the first detector 12th can be positioned close to the axis.

In all of the illustrated embodiments, for example, for a case in which the measurement object has fewer or no features on its surface, suitable features can be projected onto the surface of the measurement object to be focused, for example by reflecting them into beam paths that are already present, in particular into the first beam path 96 and / or in the second beam path 98 and / or in the imaging beam path 34 , and / or via additional beam paths.

8th shows an embodiment of the new coordinate measuring machine 61 , having one of the new sensors described 10 . The coordinate measuring machine 61 can for example be a probe arm 62 exhibit. Furthermore, the coordinate measuring machine 61 a measuring head 64 exhibit. For example, the measuring head 64 the sensor 10 exhibit. Furthermore, the coordinate measuring machine 61 a column 66 exhibit. For example, the coordinate measuring machine 61 a workpiece holder 68 as well as a base 70 exhibit. For example, the column 66 be moved relative to the measurement object, for example by means of the device for changing the focus 26th . Alternatively, the measurement object can be attached to the measurement head 64 be movable, for example by means of a movable workpiece holder 68 . The coordinate measuring machine 61 can have additional sensors. For example, the coordinate measuring machine 61 be a multi-sensor coordinate measuring machine. Using the new sensor 10 or the new kit, for example, the coordinate measuring machine 61 be focused with respect to the measurement object. For example, the distance between a sensor and the object to be measured can be set in such a way that an image quality that satisfies metrological requirements can be achieved.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016202928 [0003]
• DE 3828381 C2 [0005]
• DE 102016202928 A1 [0006]

Claims (15)

Sensor for determining the geometric properties of a measurement object which is arranged in an object space (17), the sensor (10) having an optical arrangement (14) and an evaluation and control device (16), the optical arrangement (14) having a first detector (12), the optical arrangement (14) defining a first focus profile (19) with a first maximum (39) along a first beam path line (18) in the object space (17), the optical arrangement (14) being a second focus profile (21) with a second maximum (41) along a second beam path line (25) defined in the object space (17), the evaluation and control device (16) being set up to measure a first measured value (22) of the first focus profile ( 19) and to acquire a second measured value (28) of the second focus profile (21), the evaluation and control device (16) also being set up to input a focus control from the first measured value (22) and from the second measured value (28) To determine ngs size (32), characterized in that the first focus profile (19) and the second focus profile (21) are coexisting focus profiles. Sensor after Claim 1 , wherein the evaluation and control device (16) is designed to determine the focus control input variable (32) by forming the difference between the first measured value (22) and the second measured value (28). Sensor according to one of the preceding claims, wherein the optical arrangement (14) has an imaging beam path (34), the optical arrangement (14) having a device for changing the focus (36), the evaluation and control device (16) being designed to using the focus control input variable (32) to focus the imaging beam path (34) with regard to the measurement object. Sensor after Claim 3 , wherein the device for changing the focus (36) is set up in order to focus the imaging beam path (34) with respect to the measurement object in a single step. Sensor after one of the Claims 3 or 4th , wherein the first beam path line (18) is at least partially part of the imaging beam path (34). Sensor according to one of the preceding claims, wherein the optical arrangement (14) is set up such that the first maximum (39) has a first half-width (40) and that the second maximum (41) has a second half-width (42), with Representation of the first focus profile (19) and the second focus profile (21) depending on a perpendicular projection onto an axis (60) a distance (24) between the first maximum (39) and the second maximum (41) a 0.1- to 4 times, preferably 0.5 to 2.5 times, particularly preferably 1.0 to 1.7 times the mean value of the first half width (40) and the second half width (42). Sensor according to one of the preceding claims, wherein the first detector (12) is set up to detect the first measured value (22) by means of a first light beam (20) emanating from an object, the optical arrangement (14) being set up to detect the guide the first light beam (20) along the first beam path line (18) from the object to the first detector (12), wherein the first detector (12) is further set up to measure the second measured value (28) by means of a second measured value emanating from the object To detect light beam (26), wherein the optical arrangement (18) is set up to guide the second light beam (26) along the second beam path line (25) from the object to the first detector (12), wherein the optical arrangement (14 ) is set up in such a way that an object plane of the first light beam (44) is not equal to an object plane of the second light beam (46). Sensor after Claim 7 wherein the object plane of the first light beam (44) is at an angle (48) to the object plane of the second light beam (46). Sensor after one of the Claims 7 or 8th wherein the object plane of the first light beam (44) is offset from the object plane of the second light beam (46). Sensor after one of the Claims 7 to 9 , wherein the first light beam (20) and the second light beam (26) form a light beam (50) emanating from the measurement object. Sensor after one of the Claims 7 to 10 , wherein the optical arrangement (14) has a separating device (58), wherein the separating device (58) is set up to separate the first light beam (20) from the second light beam (26). Sensor after one of the Claims 7 to 11 , wherein the optical arrangement (14) has a beam splitter (52), wherein the optical arrangement (14) is set up to superimpose the first light beam (20) with the second light beam (26) or a division by means of the beam splitter (52) of the first light beam (20) from the second light beam (26). Coordinate measuring machine having a sensor (10) according to one of the preceding claims. Kit for retrofitting a sensor for determining the geometric properties of a measurement object that is in an object space (17) is arranged, wherein the sensor has an optical arrangement (14) and an evaluation and control device (16), the optical arrangement (14) having a first detector (12), the optical arrangement (14) having an imaging beam path (34) wherein the optical arrangement (14) defines a first focus profile (19) with a first maximum (39) along the imaging beam path (34) in the object space (17), the evaluation and control device (16) being set up to a to detect the first measured value (22) of the first focus profile (19), the kit having an interface to the sensor, the kit having an optical supplementary arrangement, the optical supplementary arrangement along a second focus profile (21) with a second maximum (41) a second beam path line (25) defined in the object space (17), characterized in that the interface to the sensor is set up to the evaluation and control device (16) of the To apply a second measured value (28) of the second focus profile (21) to the sensor. A method for determining geometric properties of a measurement object, comprising the steps of: - providing a sensor (10) with an optical arrangement (14) and an evaluation and control device (16), the optical arrangement (14) having a first detector (12) wherein the optical arrangement (14) defines a first focus profile (19) with a first maximum (39) along a first beam path line (18) in the object space (17), the optical arrangement (14) having a second focus profile (21) defined with a second maximum (41) along a second beam path line (25) in the object space (17), - acquisition of a first measured value (22) of the first focus profile (19) and a second measured value (28) of the second focus profile (21) by means of the evaluation and control device (16), and - determination of a focus control input variable (32) from the first measured value (22) and from the second measured value (28) by means of the evaluation and control device (16), characterized that the first focus profile (19) and the second focus profile (21) are coexisting focus profiles.

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